Intermittent smoking (oil) on decel?

[devlmaycry]

Ok, so I did some checking around and am not sure if it's a turbo or engine issue. When I got the car a year and a half ago it had a recent head rebuild, arp studs, and cosworth head gasket. The compression numbers are unknown to me for now until prolli tomorrow when I can get a compression tester and get them.

I have an intermittent oil smoke on decel right now. I noticed it once before a few mo ago after an oil change and paid it no attention.

Then yesterday I was driving in Atlanta rush hour traffic and noticed the smell of oil. Shortly there after I noticed a big puff of oil smelling smoke when I was on the decel. I didn't notice/smell any on take off.

Today after coming back from the VA in Atlanta I noticed more of the same symptoms. The highway was fine on the way into Rome and once I hit town it got real bad for a few stop lights like nasty 80's Camaro smoker. Then cleared up for the last 10min of the trip.

I've had cars with bad rings before and they usually do it at an idle/take off. I've had bad valve seals before that smoked on start up. Yet the intermittent smoking on decel has me baffled.

The only thing I've done lately is reset the TPS to where it's supposed to be, because I had a hunting idle that I finally got around to fixing. I also painted my intercooler pipes, but that's about it.

[Unstock240]

Rings are usually a consistant issue. My old KA would smoke on hard accel or when dropping into low gear, it was rings. My car smokes every so often now but its completely random I need valve seals. I would pull your exhaust mani off and look at the valves on that side. They should be all corboned up, if slimy then i would buy valve seals. I put seals in my last KA without pulling the head. I don't know much about turbo seals and oil lines to that but that can do it too.

[devlmaycry]

Well, I just went out and looked and let the car set for a minute idling and there seems to be a bit of smoke now that looks like oil, smelled like hot on an exhaust manifold, but smells a lot like gas as it comes out of the exhaust. Tho it doesn't look black it is the thin oil looking smoke.

The only thing I did recently was reset the TPS the car has never given me issues like this before. So, Im going to go out and check the tps voltage and see where that sets. Maybe something is acting up there.

[devlmaycry]

So, TPS was a lil out of whack, so I think maybe its on its way out. Would that even cause an issue like this? Then again how could something be fine one day then this bad the next. The majority of issues I've had in the past with smokers is it start small and gets worse.

[zachattack_5491]

Oil burn on decel is usually signals a valve seal problem. I only know that's the case with non turbo cars. I'm a turbo noob lol

[Steady_One_S13]

My 5s-fe had the same problem. It smoked ugly on decel. I took the head off and noticed lots of carbon build-up and bad oily seals.

[devlmaycry]

Yep, was going through all the normal literature on running rich and smoking.

Pulled the plugs there were a little sooty, but nothing I wouldn't expect on plugs that are a year old and have around 16k on them. They def. were not black and oily like an oil issue.

Checked the maf ground was .087 supposed to be .002v. So I did the mad reground thing. It actually lowered my idle some more and fixed the rich smell from the exhaust.

It now def. smells like oil and smokes at idle more so when I romp on it. Haven't driven it around yet to see how it treats me there. I plan on doing a compression check Sunday weather willing.

[devlmaycry]

Oh, also forgot to mention that I pulled the oil cap off when it was warm and running, no smoke/bad blow by that way. Also disconnected the PCV lines and checked for any crazy blow by there, again clean. Pulled the hotpipe and checked it, I got what seemed like a lil black dust, but nothing crazy or oily like when my 300gt VR4 was dieing.

I guess on Sunday after the compression check I will look into pulling the exhaust manifold and trying to peak at the valves.

[brandon clifton]

I'll throw my vote in on valve seals / guides. Just had the heads reworked on my Ducati for the same issue (yes- I know it's a motorcycle but the principal is the same). Basically on decel you're pulling a lot of vacuum, which will suck oil in by the valve seals. Additionally the oil-soaked air isn't diluted with a hot charge of burning exhaust gas which makes it even more noticeable.
If you're interested in having your head reworked Will's Auto Machine in Chamblee is very reasonable. I think they get $175 to disassemble the head, clean it, do a 5-angle valve job and reassemble. You have to take the head to them though- they won't disassemble the motor for you.

[liquid_cool]

my guess is your running a t25 turbo with a strait pipe or a pipe with a blown out cat...the t25 turbos need a little back pressure to seal the wet style bearing area...if im correct and your running a strait pipe..you can just add the cat and solve this issue..good luck